Compressor with opposed pistons



May 8, 1945. E. lWAEBER Y V2,375,395

COMPRESSOR WITH OPPOSED PISTONS l Filed Dec. 30, 1941 2 Sheets-Sheet u l/1-7 il| y COMPRESSOR WITH OPPOSED PISTOS `Filed Dec. 30, 1941ZVShee'tS-Sheet 2 pff ' n U lNvE Ton Enf/7 ader BY v AT'roRNEY PatentedMay 8, 1945 COMPRESSOR WITH OPPOSED PISTON S Erwin Waeber, Winterthur,Switzerland,.assign` or to Sulzer Frres, Socit Anonyme, Winterthur,Switzerland Application December 30, 1941, Serial No. 424,861 'i InSwitzerland June 13, 1941 j 3 Claims.

The invention relates to a compressor with opposed pistons, particularlya scavenging pump or a charging compressorfor two-stroke opposed-`piston internal combustion engines. Y The invention provides' eachpiston with a central guide means at the end facing its opposed pistonand a partition separating the adjacent working lspaces of the twoopposed' pistons and having one column on each of its opposite faceswhich engages the central guide means of the pistons.

Preferably `the adjacent working spaces of two opposed pistons areseparated from each other by, a partition which is fitted on each Afacewith vpiston may project within the trunk piston extension. Undercertain circumstances also the partition may be formed with perforationsso 'that the working spaces of the two pistons are connected to eachother. The partition may ybe used as a displacer so thatthe clearancemay be reducedto a minimum. l

The accompanying drawings illustrate embodi 'ments of the invention, inwhich:

Fig. 1 shows acompressor according to the invention. Fig. 2 shows adetail of the compressor to a larger scale,

but also make a tightjoint. between working -spaces I and II.

In the compressor cylindertwall I the pistons 2 and 3 are moved inopposite directions by the cranks 4 and 5. The medium to be compressedthen flows from the suction space 6 through the u suction valves 1 intothe cylinder andafter being compressed passes through the deliveryvalves 8 into the pressure space 9. I

Between the adjacent working spaces I0 I I is the partition I2, whichpossesses columns .I3 and I4 respectively on the two facesV for guidingthe pistons 2 and 3. The partition is formed of two disks which are heldtogether by the bolts I5. In the groove I6 (Figs. 1 and 2) of thecylinder wall, the rings I1, made in severalpartsand slightly curved,are inserted without any gaps. When the' two disks are drawn together,these and The pistons 2 vand 3 are each fitted with a trunk pistonextension I8 andy I9 respectively at the end away from the partition,and this, together with the column, on which the piston slides, servesto guide the piston; it has a bolt for the Iconnecting rodI between` thepistons andv the crank. vIn this way aparticularly compact form ofconstruction is obtained, since the columns I3 and I4 project into thetrunk piston extensions I8 and I9 respectively.

The partition is o i such a shape that it is simultaneously usedl to actas. a displacer, 'since clearance is reduced to a mnimumand the comvpressed air can with certainty flow away unhindered through the deliveryvalves.

The described form of construction makes it possible to provide a guideat both ends of a` piston, whereby the necessary clearance can bereducedv to a minimum. The lpartition can also i be inserted withoutdivision of the cylinder. The running surfaces of the two pistons can beInachined in one o-peration.

The rings serving to maintain the partition in place in the cylindermaybe cut only at one place and be lof flexible composition. It is,however, also possible to divide the ring'into several segments whichmay then be inserted in the groove in the cylinder wall without anygaps. ticular when the ring is in several parts acompletely gas-tightpartition can be provided to separate the two adjacent working spaces,4

The inventionlmay be adopted in allpossible kinds of compressors, inparticular, however, in

the scavenging pumps and charging compressors of two-strokeopposed-pistoninternal combustion engines. i

I claim:

1. A compressor comprisingr at least one cylin-y der, a `partitiondividing the lcylinder into two working spaces, opposed pistonsreciprocating, re-

' spectively, in said spaces, means connecting the partition to thecylinder wall, a column extending from the partition into each workingspace, and a trunk piston extension iitting to each piston, each columnbeing arranged to enter a trunk piston extension and guide thepistn.

2. A compressor according to claim 1 in which` the wall of the cylinderis provided with an annular groove and in which the partition isprovided with an annular groove which cooperates rings are deformed insuch a way that they not I with the annular groove in the cylinder wall,ring means in the annular grooves for securing the partition to thecylinder wall, and means vpressfi In paring the ring means into tightengagement with ythe cylinder wall and -thepartition forming a tightjoint. i

3. A compressor according to claim 1 in which y the partition is formedof two discs, means connecting the two discs together; ythe two discsforming an annular disc between them, the cylinder wall having anannular groove cooperating said curved vrings being pressed into tightengagement with the partition discs and with the cylinder wall when thediscs are held together by the

